Improvement in fire-proof chests and safes



UNITED STATES PATENT ()FFIcE.

DANIEL FITZGERALD, OF NEW YORK, N. Y., ASSIGNOR TO ENOS WILDER.

IMPROVEMENT IN FIRE-PROOF CHESTS AND SAFES.

Specification forming part of Letters Patent No. 3,117, dated June 1,lei-'3.

To all whom it may concern:

Be it known that l, DANIEL FITZGERALD, of the city, county, and State ofNew York, and a citizen of the United States, have discovered and madean Improvement (new and useful) in the Construction of Iron Chests orSafes, intended to resist the action of fire and for the safe keepingand preserving books and papers and other valuables from destruction byfire,which I call a- Salamander Safe or Chest.

The following is a full and exact description of the safe or chest withmy improvement coinbincd therewith.

I make two iron chests in the common and ordinary way of making ironchests, which is well known to those engaged in this branch of business,one smaller than the other, which, when the safe is to put together,forms the inner chest or inner part of the safe. The other chest is madeaboutthree inches larger than the inner one, and so as, when puttogether, it will form the outer part or crust of the safe and leave aspace between the inner and outer chest of the safe of about threeinches, which space may vary a little (more or less) when the chests areput together, but should be the same all round and in every direction.The inner and outer doors, where twodoors are used, are prepared in thesame way, leaving a space, as above, between the inner and outer crustof each door, which space is left for a like purpose with that leftbetween the inner and outer chest of the safe. Where one door is used itshould be made in the same manner, leaving a like space between theinner and outer crust or face of the door, and for a like purpose,andshould be fitted to the chest or safe with great accuracy.

The edges and openings for the doors are to be neatly finished, as inother chests. I then take plasterot paris or gypsum, and having boiledit or baked it in an oven and calcined it and reduced it to a powder, I'mix it with water till it is about the consistency of cream or thinpaste, so fluid as that -it may readily be poured into the space left asabove to receive it, and I then fill all the space with theplaster-of-paris, putting in some sheets of mica between the inner andouter chest, to aid, if necessary, in checking the progress of the heatbut where pains are taken to have all the space left for the purposeproperly filled with the plaster-of-paris as above, so that, when set,it will expand and adhere firmly to the surrounding parts and completelyfill the whole space and all the cracks and points, the mica may bedispensed with and every other substance, and the plaster may he usedalone. It may also be reduced to a powder without being prepared asabove and used in that state; but I have not found it as good. The innercase or chest may be made of wood instead of iron,

as for a book-case,and the space left between that and the outer chest,filled in the manner and with the materials above named, will make avery durable safe, that will efi'ectually resist the tire, as I havefound by experience; but the safe may not be so strong or durable,though somewhat cheaper.

The above composition or preparation of gypsum may be mixed with severalother articles not contrary to its nature with a view to increase itsefiicacy in resisting the action of fire; but from my experience I doubtit they have much effect. The gypsum alone, when properly prepared andproperly placed in the space left to receive it and made to fill itcompletely, is quite sufficient to resist for a long space of time themost intense heat. The chemical properties of this article are such thatby the app ication of intense heat it imparts a vapor or gas or someother properties which effectually stay the progress of the fire andarrest the influence and effects of the heat. This I have ascertained byvarious experiments, and I believe I am the tirstman that discovered theutility and devised the method of applying gypsum or theplaster-of-paris to increase the safety of an iron chest.

I am not aware that this article was ever used for the purposes aboveset forth until I used it in manner above described.

I therefore claim as my discovery and invention and improvement- Theapplication and use of plaster-of-paris or gypsum in its raw state, orprepared as above, either alone or with mica, in the construction of alliron chests or safes, in the manner above described or in any othermanner substantially the same.

DANIEL FITZGERALD.

In presence of G. H. PATTERSON, BEVERLY ROBINSON, Jr.

